Investigators: Scotland and London Bomb Attempts Linked to Same Two Men

British investigators' leading theory is that the same two persons attempted the downtown London bombings early Friday morning and then traveled to Glasgow where they attempted what now appears to be a failed suicide attack on Glasgow Airport, ABC News has learned. According to British authorities, the two men under the spotlight are both doctors and part of a group of eight doctors, residents and other medical personnel believed to have planned, executed and supported the two sets of thwarted attacks, including two men who are brothers -- Dr. Khalid Ahmed and Dr. Sabeel Ahmed -- sources in Britain tell ABC News.

The attacks were less than 14 hours apart.

It is unclear whether the Glasgow attack was hastily put together when the London attacks were thwarted.

But several factors, authorities said, point to that possibility, including the fact that the bombs were not rigged to a sophisticated firing mechanism, as were the ones in London. One of the occupants was so badly burned that authorities were unable to determine at first whether he was armed with a suicide belt or not. Some of his charred possessions suggested at first that he might have been wearing such a belt. That led to preparation to evacuate the hospital where he was treated. Ultimately, it was determined he was not wearing an explosive belt and the hospital was not evacuated.

Authorities are now sorting through medical school records, travel records and school records of all of the persons linked to the plot -- however tangentially -- in an effort to see where the nexus of the cell formed. Six hours before the Glasgow attack, police had traced the drivers of the Jeep that rammed the airport terminal to a taxi company in Glasgow, using cell phones left in the London cars. One of the bombers, Dr. Bilal Abdulla, had called the company just two weeks earlier and was recorded requesting a cab to the airport.

Authorities are also scouring Internet chat rooms and jihadists' message boards to determine what postings were made by any group members, and to see how those postings might be related to the method of the attack, and the rationale for it. Speculation on the motive has included anger over a Dutch newspaper's past publication of a cartoon deemed offensive by many Muslims, the knighting of novelist Salman Rushdie, still marked for death by some extreme
Muslims, and an effort to sway newly installed Prime Minister Gordon Brown to stop supporting the American foreign policy.

According to well-placed sources in both U.S. and foreign law enforcement and intelligence agencies, previously unsubstantiated reports of links to the United States and to Canada appear to be more tenuous than firm at this time. It appears one person detained in Australia has expressed an interest in traveling to Canada, but there is no Canadian citizen or resident currently known to be a member of the cell, nor any danger within Canada related to the cell. Links to the United States are also said to be tenuous, and authorities are investigating to see if they amount to anything.

While the plotters appear to be highly trained professionals with no established, firm links to al Qaeda's operational hierarchy at this time, authorities caution that neither this, nor the choice of an incendiary device that failed to work should suggest these were amateurs. The reality is the plotters caught authorities by surprise, and they seemed to receive no prior intelligence indicating an attack was imminent. From the point of view of intelligence experts who have spoken to ABC News, that makes the attacks successful, even if there were no casualties.